In Diary of a Wimpy Kid Hard Luck, why does Greg's best friend Rowley Jefferson have a girlfriend?

Remember Miles, in the last book, Greg tried to go with Abigail to the Valentine's Day dance, but had NO luck. now, instead of hanging out with Greg, Rowley ditched Greg and now Greg feels completely lost. So, at school, Greg says that they turned the Bully station to a "Find a Friend" station because Greg doesn't have a lot of choices these days, so he presses the button, and instead of a student coming, Mr. NERN comes and plays checkers with Greg until lunch is over.